EP-A-495547 describes reactions in which optionally substituted olefinically unsaturated compounds are reacted with carbon monoxide and a co-reactant in the presence of a catalyst system comprising a source of palladium-cations, a source of specific aliphatic bidentate diphosphines and a source of anions. The co-reactant of EP-A-495547 is, in the terminology of the present invention, the nucleophilic component. A variety of products are also described in the patent. These products are produced in accordance with disclosed carbonylation reactions depending upon the reactants, the prevailing reaction conditions and the selected catalyst system. The relative amounts of co-reactants, the composition of the diphosphine ligand and on the source of anions also greatly enhances or suppresses the production of these varying products.
While one skilled in the art can generally obtain desired products in reasonably good yields based on the teachings of EP-A-495547 and EP-186,228A1, it would be desirable to improve yields based on catalyst usage. This greatly effects the commercial viability of these methods. Accordingly, improving such yields without impeding such factors as selectivity, reaction rates, and catalyst stability continues to be a highly sought goal.
It is therefore an object of this invention to provide a process for the carbonylation of acetylene by the reaction of carbon monoxide and a nucleophilic compound to for acrylic acid or an ester thereof.
It is a further object of this invention to provide a carbonylation reaction with an improved rate of reaction or yield based on catalyst over prior art processes.
It is a yet further object of this invention to provide a catalyst system for the carbonylation of acetylene the reaction of carbon monoxide and a nucleophilic compound with the presence of hydrogen.